Recently, portable devices have provided various functions needed by users, such as a call function, an image or video capturing function, a broadcasting reception function, an Internet connection function, and so forth.
Meanwhile, recent portable devices (hereinafter, referred to as source devices) provide a wireless image transmission function capable of transmitting multimedia contents (that is, video, audio, texts, and the like) to other devices (hereinafter, referred to as sink devices) through wireless communication (for example, Wireless Fidelity (Wi-Fi), Bluetooth, a mobile communication network, or the like). Examples of the wireless image transmission function may include Wi-Fi Display (WFD), Wireless Display (Wi-Di), Miracast, and so forth.
The wireless image transmission function generally transmits multimedia contents on a real-time basis. As such, when transmitting the multimedia contents to the sink device on a real time basis, the source device stores data by a predetermined size (or time) in a buffer and then plays data to avoid fluctuation characteristics of a wireless communication channel and to provide a continuous screen.
Herein, if the sink device receives a control command for controlling a play position of the source device from a user, the source device checks the play position corresponding to the control command and seeks again multimedia contents from the checked play position. The source device transcodes a screen of the source device and retransmits the multimedia contents from the checked play position even though the same multimedia contents have already been transmitted to the sink device. Therefore, a need exists for a scheme for effectively retransmitting multimedia contents from the source device to the sink device.